Golf is a game that is played and enjoyed by millions of people around the world. It is therefore understandable that much attention has been given over the years to improving the equipment that is used to play the game. Improvements in playing equipment have resulted in better scores for many people and equipment that is more serviceable and less prone to damage or absolute failure, all of which have led to an increased enjoyment of the game.
A notable development in the art of golf clubs was the introduction of the metal driver, or "metal wood" as disclosed in U.S. Pat. No. 4,214,754. As shown therein, a head for a golf metal wood is in the form of a one piece hollow enclosed metal body which includes a heel and a toe, a face and a back, a sole and a topside, and a neck or hosel, which is integral with the club body and extends generally upwardly therefrom, for receiving a shaft. Other significant developments include the hosel-less wood golf club of U.S. Pat. No. 3,810,621 and the hosel-less metal wood of U.S. Pat. No. 5,042,806. Many other improvements have been made in golf clubs as illustrated by U.S. Pat. Nos. 581,331,645,944, 1,868,286, 4,429,879, 4,438,931, Des. 93,862, Des. 216,030, and Des. 318,087.
In conventional practice a bore is provided in the club head of a metal wood and extends from an upper shalt-receiving opening in a hosel either to or toward the bottom surface or sole of the head. In the latter case, the bore may terminate in an end wall which is above the bottom surface or sole of the head. A hosel-less metal wood also has a bore which extends from an upper shaft receiving opening, which in that case is provided in the top surface of the club head body.
One problem that has been encountered in metal woods is stress fractures of the shaft. The shaft flexes slightly as a player swings a club. When the club head strikes a ball, the impact stresses the shaft at the upper end of the bore, which is at the upper end of a hosel in a conventional golf club and at the top surface of the club in a hosel-less golf club. The club becomes weakened at this point over time and eventually may fracture. This mode of failure is particularly a problem in a golf club in which the diameter of the bore is uniform over its entire length.
One approach to alleviate this problem has been to provide a tapered countersink in the bore just below upper opening in the hosel. The shaft is inserted into the club head through the hosel and fixedly attached therein with an adhesive. A rubber O-ring is placed at the interlace of the hosel and the shaft, thus hiding the glue joint and providing a neat, finished appearance. The O-ring is only for aesthetic purposes, and the adhesive holding it in place often breaks loose allowing the O-ring to slide up and down the shaft and requiring that it be glued back in place. Also, when the adhesive breaks loose, the shall is no longer cushioned at the intersection with the upper end of a hosel (or the top surface of a hosel-less golf club) so that stress which may ultimately lead to fracture is placed on the shall at this location.
As will become apparent in the disclosure which follows, the present invention provides an improvement over this convention practice.